The present technique relates to communication in redundancy management LAN (local area network) environments in network systems for business entities and so on. The present technique relates to a communication management program for causing a computer to execute processing for managing communication with client apparatuses through a network and for responding to a predetermined request received from each client apparatus and also to a communication management method and a communication management apparatus which implement the communication management program.
In order to improve the management efficiency through computerization of correspondence and so on in business activities, network systems, such as LANs (e.g., Japanese Unexamined Patent Application Publication No. 2003-273885) is build. When a LAN is installed in a business entity as a network system, it is common to provide the LAN with redundancy for, for example, a network-system downtime due to a failure.
A known technology for a redundancy management LAN will be briefly described with reference to FIG. 7. As illustrated in FIG. 7, a client apparatus is quipped with redundancy LAN cards, which include a LAN card A 102 (e.g., LAN A) that is usually used for communication through a LAN and a LAN card B 104 (e.g., LAN B) that is used, through switching, for communication with a management server when the LAN card A fails.
The management server shown in FIG. 7 pre-registers, in a management table, a MAC (media access control) address (e.g., MAC A 202) associated with the LAN card A that is usually used by the client apparatus.
For example, upon receiving a PXE (Preboot eXecution Environment) startup request or the like from the client apparatus, the management server determines whether or not a MAC address indicating the transmission source of the request is already registered in the management table. When the MAC address indicating the transmission source and the MAC address registered in the management table match each other, the management server responds to the request, and when the MAC addresses do not match each other, the management server rejects the request.
There is a Japanese Laid-open Patent Publication No. 2003-273885.
However, in the known technology, the management server cannot respond to a case in which switching between LAN cards is performed at the client apparatus, and thus has a problem of rejecting a request from the client apparatus.
That is, as shown in FIG. 8, when the LAN card A fails, the client apparatus performs switching from the LAN card A to the LAN card B and transmits, to the management server, a request for permitting the LAN card B as a transmission source. Upon receiving the request from the client apparatus, however, the management server rejects the request from the client, when a MAC address (e.g., MAC B 204) indicating the transmission source of the request does not match a MAC address (e.g., MAC A) registered in the management table. The known technology, therefore, has a problem in that communication may not be established between the management server and the client apparatus.